R/gs-app/server.R

In kmcd39/diVis:

# server -----------------------------------------------------------------
server <- function(input, output, session) {

  # global reactives -------------------------------------------------------------

  # region can be zoomed into to show CT bkdwn. Option to zoom can happen various
  # places, so stored globally as reactive list
  selected_region <- reactiveVal(NULL)
  selected_CTs <- reactiveVal(NULL)

  # render base leaflet & define proxy & interaction list -------------------------
  output$map <- renderLeaflet({
    create_leaflet_base()
  })
  # set proxy
  prox <- leafletProxy("map")
  # set initial zoom (lower 48 states)in
  do.call('fitBounds',
          c(list(map = prox), l48bbox))

  # interaction seems to have to exist in main server call due to leaflet+shiny
  # design so I save as reactive list. I'm not sure why this is and am curious
  leaflet_interaction <- reactiveValues()

  # observer for map click + zoom. Can pass this onto modules where necessary.
  observeEvent( list(input$map_shape_click, input$map_zoom), {
    leaflet_interaction$click_info <- input$map_shape_click
    leaflet_interaction$zoom_level <- input$map_zoom
  })
  # -------------------------------------------------------------------------

  # call modules ------------------------------------------------------------

  # parse core input using geoseg module
  c(gs.out, gs.palette) %<-%
    mod_geoseg("gs")

  # send to map using leaflet module
  mod_geoseg_leaflet("gs",
                     gs.out, show_CTs = selected_CTs,
                     gs.palette, prox)

  # parse leaflet interaction. This sets selected_region when user zooms out or
  # clicks a region.
  mod_parse_leaflet.interaction("gs",
                                gs.out,
                                show_CTs = selected_CTs,
                                leaflet_interaction = leaflet_interaction,
                                selection.reactive = selected_region,
                                prox)

  # updates selected_CTs and sets zoom when selected_region is updated
  mod_region2CTs("gs",
                 region.reactive = selected_region,
                 CT.reactive = selected_CTs,
                 prox)

  # division overlay module - DB requires credentials or alt setup so not currently
  # included in deployed version.
  # mod_div_overlay_server("gs", selected_CTs, prox)

  # filter population module
  pop.filtered.gs <-
    mod_population.filter("gs", gs.out)


  mod_point.histogram("gs",
                      pop.filtered.gs,
                      gs.palette,
                      selection.reactive = selected_region,
                      hilite.point = reactiveVal(NULL),
                      change_in = FALSE)

  # happens outside of module because dealing across UI elements
  observeEvent(selected_region(), {
    # switches to map tab when a zoom region is selected from different tab
    if(!is.null(selected_region()) & input$main_display != "map")
      updateSelectInput(session, "main_display",
                        selected = "map")
  })

  }


# launch -----------------------------------------------------------------------
#shinyApp(ui, server)
#full.app <- function() {
#  shinyApp(gs_ui, gs_server)
#}

#full.app()